LED lighting has advantages of high efficiency and energy-saving. The luminous efficiency of the most of the current LED lights may be more than 70 LM/W, and thus the current LED lights may save more energy than conventional energy-saving lamps. Theoretically, the luminous efficiency of a green LED can be up to 683 LM/W; and the luminous efficiency of a white LED may be up to 182.45 LM/W. Compared with the 360 degree luminous way of the conventional lighting, LED is a unidirectional point light source and thus its lighting direction may be easily and optically controlled. In this regard, the lighting efficiency of LED is much higher than the same of the conventional lighting device. In addition, the color rendering of LED is also higher than the same of the conventional lighting device, and it is easy to implement light illumination control for LED, which makes a massive promotion development space of LED lighting. However, the overheating of LED will cause its luminous efficiency drops rapidly so as to form a so-called “Lumens Depreciation”. The withstanding voltage of a LED is about 3.2 V (3.0˜3.5 V). Theoretically, light output of the LED is associated with the drive current, and is independent of the power supply voltage. Unstable supply of the drive current will make the LED overheating, such that the luminous efficiency of the overheated LED drops rapidly so as to form a so-called “Lumens Depreciation”.
The supply voltage of most exiting LED optical modules is lower than 48 V. In order to achieve constant current effect, the most of the power supply circuits has a complex structure, a low efficiency and a high cost. This causes the structure of the LED lights is large and the price is high. Therefore, the development of the LED light is limited to a certain extent.
Additionally, under the current LED light design, a LED chip is packaged into a separate chip module. A bridge rectifier, a rectifier diode, and a constant current diode also are packaged into separate elements, respectively. The lighting manufacturers first incorporate these independent elements onto a circuit board to form an integrated LED circuit board, and then assemble the LED circuit board with a light body together to form a LED light. Therefore, the whole production process becomes a long-time process with a high cost and a low efficiency.